Trace picture piles on layers

cc/layers/picture_layer_impl.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/picture_layer_impl.h"
 
 #include <algorithm>
 
 #include "base/time.h"
 #include "cc/base/math_util.h"
@@ skipping 936 matching lines @@
     SkColor* color,
     float* width) const {
   *color = DebugColors::TiledContentLayerBorderColor();
   *width = DebugColors::TiledContentLayerBorderWidth(layer_tree_impl());
 }
 
 void PictureLayerImpl::AsValueInto(base::DictionaryValue* state) const {
   LayerImpl::AsValueInto(state);
   state->SetDouble("ideal_contents_scale", ideal_contents_scale_);
   state->Set("tilings", tilings_->AsValue().release());
+  state->Set("pictures", pile_->AsValue().release());
   state->Set("invalidation", invalidation_.AsValue().release());
 }
 
 }  // namespace cc